xref: /openbmc/linux/net/ipv6/ip6_gre.c (revision 3a83e4e6)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	GRE over IPv6 protocol decoder.
4  *
5  *	Authors: Dmitry Kozlov (xeb@mail.ru)
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/capability.h>
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/slab.h>
15 #include <linux/uaccess.h>
16 #include <linux/skbuff.h>
17 #include <linux/netdevice.h>
18 #include <linux/in.h>
19 #include <linux/tcp.h>
20 #include <linux/udp.h>
21 #include <linux/if_arp.h>
22 #include <linux/init.h>
23 #include <linux/in6.h>
24 #include <linux/inetdevice.h>
25 #include <linux/igmp.h>
26 #include <linux/netfilter_ipv4.h>
27 #include <linux/etherdevice.h>
28 #include <linux/if_ether.h>
29 #include <linux/hash.h>
30 #include <linux/if_tunnel.h>
31 #include <linux/ip6_tunnel.h>
32 
33 #include <net/sock.h>
34 #include <net/ip.h>
35 #include <net/ip_tunnels.h>
36 #include <net/icmp.h>
37 #include <net/protocol.h>
38 #include <net/addrconf.h>
39 #include <net/arp.h>
40 #include <net/checksum.h>
41 #include <net/dsfield.h>
42 #include <net/inet_ecn.h>
43 #include <net/xfrm.h>
44 #include <net/net_namespace.h>
45 #include <net/netns/generic.h>
46 #include <net/rtnetlink.h>
47 
48 #include <net/ipv6.h>
49 #include <net/ip6_fib.h>
50 #include <net/ip6_route.h>
51 #include <net/ip6_tunnel.h>
52 #include <net/gre.h>
53 #include <net/erspan.h>
54 #include <net/dst_metadata.h>
55 
56 
57 static bool log_ecn_error = true;
58 module_param(log_ecn_error, bool, 0644);
59 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
60 
61 #define IP6_GRE_HASH_SIZE_SHIFT  5
62 #define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT)
63 
64 static unsigned int ip6gre_net_id __read_mostly;
65 struct ip6gre_net {
66 	struct ip6_tnl __rcu *tunnels[4][IP6_GRE_HASH_SIZE];
67 
68 	struct ip6_tnl __rcu *collect_md_tun;
69 	struct ip6_tnl __rcu *collect_md_tun_erspan;
70 	struct net_device *fb_tunnel_dev;
71 };
72 
73 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
74 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly;
75 static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly;
76 static int ip6gre_tunnel_init(struct net_device *dev);
77 static void ip6gre_tunnel_setup(struct net_device *dev);
78 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
79 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
80 static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu);
81 
82 /* Tunnel hash table */
83 
84 /*
85    4 hash tables:
86 
87    3: (remote,local)
88    2: (remote,*)
89    1: (*,local)
90    0: (*,*)
91 
92    We require exact key match i.e. if a key is present in packet
93    it will match only tunnel with the same key; if it is not present,
94    it will match only keyless tunnel.
95 
96    All keysless packets, if not matched configured keyless tunnels
97    will match fallback tunnel.
98  */
99 
100 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(IP6_GRE_HASH_SIZE - 1))
101 static u32 HASH_ADDR(const struct in6_addr *addr)
102 {
103 	u32 hash = ipv6_addr_hash(addr);
104 
105 	return hash_32(hash, IP6_GRE_HASH_SIZE_SHIFT);
106 }
107 
108 #define tunnels_r_l	tunnels[3]
109 #define tunnels_r	tunnels[2]
110 #define tunnels_l	tunnels[1]
111 #define tunnels_wc	tunnels[0]
112 
113 /* Given src, dst and key, find appropriate for input tunnel. */
114 
115 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
116 		const struct in6_addr *remote, const struct in6_addr *local,
117 		__be32 key, __be16 gre_proto)
118 {
119 	struct net *net = dev_net(dev);
120 	int link = dev->ifindex;
121 	unsigned int h0 = HASH_ADDR(remote);
122 	unsigned int h1 = HASH_KEY(key);
123 	struct ip6_tnl *t, *cand = NULL;
124 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
125 	int dev_type = (gre_proto == htons(ETH_P_TEB) ||
126 			gre_proto == htons(ETH_P_ERSPAN) ||
127 			gre_proto == htons(ETH_P_ERSPAN2)) ?
128 		       ARPHRD_ETHER : ARPHRD_IP6GRE;
129 	int score, cand_score = 4;
130 	struct net_device *ndev;
131 
132 	for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
133 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
134 		    !ipv6_addr_equal(remote, &t->parms.raddr) ||
135 		    key != t->parms.i_key ||
136 		    !(t->dev->flags & IFF_UP))
137 			continue;
138 
139 		if (t->dev->type != ARPHRD_IP6GRE &&
140 		    t->dev->type != dev_type)
141 			continue;
142 
143 		score = 0;
144 		if (t->parms.link != link)
145 			score |= 1;
146 		if (t->dev->type != dev_type)
147 			score |= 2;
148 		if (score == 0)
149 			return t;
150 
151 		if (score < cand_score) {
152 			cand = t;
153 			cand_score = score;
154 		}
155 	}
156 
157 	for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
158 		if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
159 		    key != t->parms.i_key ||
160 		    !(t->dev->flags & IFF_UP))
161 			continue;
162 
163 		if (t->dev->type != ARPHRD_IP6GRE &&
164 		    t->dev->type != dev_type)
165 			continue;
166 
167 		score = 0;
168 		if (t->parms.link != link)
169 			score |= 1;
170 		if (t->dev->type != dev_type)
171 			score |= 2;
172 		if (score == 0)
173 			return t;
174 
175 		if (score < cand_score) {
176 			cand = t;
177 			cand_score = score;
178 		}
179 	}
180 
181 	for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
182 		if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
183 			  (!ipv6_addr_equal(local, &t->parms.raddr) ||
184 				 !ipv6_addr_is_multicast(local))) ||
185 		    key != t->parms.i_key ||
186 		    !(t->dev->flags & IFF_UP))
187 			continue;
188 
189 		if (t->dev->type != ARPHRD_IP6GRE &&
190 		    t->dev->type != dev_type)
191 			continue;
192 
193 		score = 0;
194 		if (t->parms.link != link)
195 			score |= 1;
196 		if (t->dev->type != dev_type)
197 			score |= 2;
198 		if (score == 0)
199 			return t;
200 
201 		if (score < cand_score) {
202 			cand = t;
203 			cand_score = score;
204 		}
205 	}
206 
207 	for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
208 		if (t->parms.i_key != key ||
209 		    !(t->dev->flags & IFF_UP))
210 			continue;
211 
212 		if (t->dev->type != ARPHRD_IP6GRE &&
213 		    t->dev->type != dev_type)
214 			continue;
215 
216 		score = 0;
217 		if (t->parms.link != link)
218 			score |= 1;
219 		if (t->dev->type != dev_type)
220 			score |= 2;
221 		if (score == 0)
222 			return t;
223 
224 		if (score < cand_score) {
225 			cand = t;
226 			cand_score = score;
227 		}
228 	}
229 
230 	if (cand)
231 		return cand;
232 
233 	if (gre_proto == htons(ETH_P_ERSPAN) ||
234 	    gre_proto == htons(ETH_P_ERSPAN2))
235 		t = rcu_dereference(ign->collect_md_tun_erspan);
236 	else
237 		t = rcu_dereference(ign->collect_md_tun);
238 
239 	if (t && t->dev->flags & IFF_UP)
240 		return t;
241 
242 	ndev = READ_ONCE(ign->fb_tunnel_dev);
243 	if (ndev && ndev->flags & IFF_UP)
244 		return netdev_priv(ndev);
245 
246 	return NULL;
247 }
248 
249 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
250 		const struct __ip6_tnl_parm *p)
251 {
252 	const struct in6_addr *remote = &p->raddr;
253 	const struct in6_addr *local = &p->laddr;
254 	unsigned int h = HASH_KEY(p->i_key);
255 	int prio = 0;
256 
257 	if (!ipv6_addr_any(local))
258 		prio |= 1;
259 	if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
260 		prio |= 2;
261 		h ^= HASH_ADDR(remote);
262 	}
263 
264 	return &ign->tunnels[prio][h];
265 }
266 
267 static void ip6gre_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
268 {
269 	if (t->parms.collect_md)
270 		rcu_assign_pointer(ign->collect_md_tun, t);
271 }
272 
273 static void ip6erspan_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
274 {
275 	if (t->parms.collect_md)
276 		rcu_assign_pointer(ign->collect_md_tun_erspan, t);
277 }
278 
279 static void ip6gre_tunnel_unlink_md(struct ip6gre_net *ign, struct ip6_tnl *t)
280 {
281 	if (t->parms.collect_md)
282 		rcu_assign_pointer(ign->collect_md_tun, NULL);
283 }
284 
285 static void ip6erspan_tunnel_unlink_md(struct ip6gre_net *ign,
286 				       struct ip6_tnl *t)
287 {
288 	if (t->parms.collect_md)
289 		rcu_assign_pointer(ign->collect_md_tun_erspan, NULL);
290 }
291 
292 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
293 		const struct ip6_tnl *t)
294 {
295 	return __ip6gre_bucket(ign, &t->parms);
296 }
297 
298 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
299 {
300 	struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
301 
302 	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
303 	rcu_assign_pointer(*tp, t);
304 }
305 
306 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
307 {
308 	struct ip6_tnl __rcu **tp;
309 	struct ip6_tnl *iter;
310 
311 	for (tp = ip6gre_bucket(ign, t);
312 	     (iter = rtnl_dereference(*tp)) != NULL;
313 	     tp = &iter->next) {
314 		if (t == iter) {
315 			rcu_assign_pointer(*tp, t->next);
316 			break;
317 		}
318 	}
319 }
320 
321 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
322 					   const struct __ip6_tnl_parm *parms,
323 					   int type)
324 {
325 	const struct in6_addr *remote = &parms->raddr;
326 	const struct in6_addr *local = &parms->laddr;
327 	__be32 key = parms->i_key;
328 	int link = parms->link;
329 	struct ip6_tnl *t;
330 	struct ip6_tnl __rcu **tp;
331 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
332 
333 	for (tp = __ip6gre_bucket(ign, parms);
334 	     (t = rtnl_dereference(*tp)) != NULL;
335 	     tp = &t->next)
336 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
337 		    ipv6_addr_equal(remote, &t->parms.raddr) &&
338 		    key == t->parms.i_key &&
339 		    link == t->parms.link &&
340 		    type == t->dev->type)
341 			break;
342 
343 	return t;
344 }
345 
346 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
347 		const struct __ip6_tnl_parm *parms, int create)
348 {
349 	struct ip6_tnl *t, *nt;
350 	struct net_device *dev;
351 	char name[IFNAMSIZ];
352 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
353 
354 	t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
355 	if (t && create)
356 		return NULL;
357 	if (t || !create)
358 		return t;
359 
360 	if (parms->name[0]) {
361 		if (!dev_valid_name(parms->name))
362 			return NULL;
363 		strlcpy(name, parms->name, IFNAMSIZ);
364 	} else {
365 		strcpy(name, "ip6gre%d");
366 	}
367 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
368 			   ip6gre_tunnel_setup);
369 	if (!dev)
370 		return NULL;
371 
372 	dev_net_set(dev, net);
373 
374 	nt = netdev_priv(dev);
375 	nt->parms = *parms;
376 	dev->rtnl_link_ops = &ip6gre_link_ops;
377 
378 	nt->dev = dev;
379 	nt->net = dev_net(dev);
380 
381 	if (register_netdevice(dev) < 0)
382 		goto failed_free;
383 
384 	ip6gre_tnl_link_config(nt, 1);
385 
386 	/* Can use a lockless transmit, unless we generate output sequences */
387 	if (!(nt->parms.o_flags & TUNNEL_SEQ))
388 		dev->features |= NETIF_F_LLTX;
389 
390 	dev_hold(dev);
391 	ip6gre_tunnel_link(ign, nt);
392 	return nt;
393 
394 failed_free:
395 	free_netdev(dev);
396 	return NULL;
397 }
398 
399 static void ip6erspan_tunnel_uninit(struct net_device *dev)
400 {
401 	struct ip6_tnl *t = netdev_priv(dev);
402 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
403 
404 	ip6erspan_tunnel_unlink_md(ign, t);
405 	ip6gre_tunnel_unlink(ign, t);
406 	dst_cache_reset(&t->dst_cache);
407 	dev_put(dev);
408 }
409 
410 static void ip6gre_tunnel_uninit(struct net_device *dev)
411 {
412 	struct ip6_tnl *t = netdev_priv(dev);
413 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
414 
415 	ip6gre_tunnel_unlink_md(ign, t);
416 	ip6gre_tunnel_unlink(ign, t);
417 	if (ign->fb_tunnel_dev == dev)
418 		WRITE_ONCE(ign->fb_tunnel_dev, NULL);
419 	dst_cache_reset(&t->dst_cache);
420 	dev_put(dev);
421 }
422 
423 
424 static int ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
425 		       u8 type, u8 code, int offset, __be32 info)
426 {
427 	struct net *net = dev_net(skb->dev);
428 	const struct ipv6hdr *ipv6h;
429 	struct tnl_ptk_info tpi;
430 	struct ip6_tnl *t;
431 
432 	if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IPV6),
433 			     offset) < 0)
434 		return -EINVAL;
435 
436 	ipv6h = (const struct ipv6hdr *)skb->data;
437 	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
438 				 tpi.key, tpi.proto);
439 	if (!t)
440 		return -ENOENT;
441 
442 	switch (type) {
443 	case ICMPV6_DEST_UNREACH:
444 		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
445 				    t->parms.name);
446 		if (code != ICMPV6_PORT_UNREACH)
447 			break;
448 		return 0;
449 	case ICMPV6_TIME_EXCEED:
450 		if (code == ICMPV6_EXC_HOPLIMIT) {
451 			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
452 					    t->parms.name);
453 			break;
454 		}
455 		return 0;
456 	case ICMPV6_PARAMPROB: {
457 		struct ipv6_tlv_tnl_enc_lim *tel;
458 		__u32 teli;
459 
460 		teli = 0;
461 		if (code == ICMPV6_HDR_FIELD)
462 			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
463 
464 		if (teli && teli == be32_to_cpu(info) - 2) {
465 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
466 			if (tel->encap_limit == 0) {
467 				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
468 						    t->parms.name);
469 			}
470 		} else {
471 			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
472 					    t->parms.name);
473 		}
474 		return 0;
475 	}
476 	case ICMPV6_PKT_TOOBIG:
477 		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
478 		return 0;
479 	case NDISC_REDIRECT:
480 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
481 			     sock_net_uid(net, NULL));
482 		return 0;
483 	}
484 
485 	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
486 		t->err_count++;
487 	else
488 		t->err_count = 1;
489 	t->err_time = jiffies;
490 
491 	return 0;
492 }
493 
494 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
495 {
496 	const struct ipv6hdr *ipv6h;
497 	struct ip6_tnl *tunnel;
498 
499 	ipv6h = ipv6_hdr(skb);
500 	tunnel = ip6gre_tunnel_lookup(skb->dev,
501 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
502 				      tpi->proto);
503 	if (tunnel) {
504 		if (tunnel->parms.collect_md) {
505 			struct metadata_dst *tun_dst;
506 			__be64 tun_id;
507 			__be16 flags;
508 
509 			flags = tpi->flags;
510 			tun_id = key32_to_tunnel_id(tpi->key);
511 
512 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id, 0);
513 			if (!tun_dst)
514 				return PACKET_REJECT;
515 
516 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
517 		} else {
518 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
519 		}
520 
521 		return PACKET_RCVD;
522 	}
523 
524 	return PACKET_REJECT;
525 }
526 
527 static int ip6erspan_rcv(struct sk_buff *skb,
528 			 struct tnl_ptk_info *tpi,
529 			 int gre_hdr_len)
530 {
531 	struct erspan_base_hdr *ershdr;
532 	const struct ipv6hdr *ipv6h;
533 	struct erspan_md2 *md2;
534 	struct ip6_tnl *tunnel;
535 	u8 ver;
536 
537 	ipv6h = ipv6_hdr(skb);
538 	ershdr = (struct erspan_base_hdr *)skb->data;
539 	ver = ershdr->ver;
540 
541 	tunnel = ip6gre_tunnel_lookup(skb->dev,
542 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
543 				      tpi->proto);
544 	if (tunnel) {
545 		int len = erspan_hdr_len(ver);
546 
547 		if (unlikely(!pskb_may_pull(skb, len)))
548 			return PACKET_REJECT;
549 
550 		if (__iptunnel_pull_header(skb, len,
551 					   htons(ETH_P_TEB),
552 					   false, false) < 0)
553 			return PACKET_REJECT;
554 
555 		if (tunnel->parms.collect_md) {
556 			struct erspan_metadata *pkt_md, *md;
557 			struct metadata_dst *tun_dst;
558 			struct ip_tunnel_info *info;
559 			unsigned char *gh;
560 			__be64 tun_id;
561 			__be16 flags;
562 
563 			tpi->flags |= TUNNEL_KEY;
564 			flags = tpi->flags;
565 			tun_id = key32_to_tunnel_id(tpi->key);
566 
567 			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id,
568 						  sizeof(*md));
569 			if (!tun_dst)
570 				return PACKET_REJECT;
571 
572 			/* skb can be uncloned in __iptunnel_pull_header, so
573 			 * old pkt_md is no longer valid and we need to reset
574 			 * it
575 			 */
576 			gh = skb_network_header(skb) +
577 			     skb_network_header_len(skb);
578 			pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
579 							    sizeof(*ershdr));
580 			info = &tun_dst->u.tun_info;
581 			md = ip_tunnel_info_opts(info);
582 			md->version = ver;
583 			md2 = &md->u.md2;
584 			memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
585 						       ERSPAN_V2_MDSIZE);
586 			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
587 			info->options_len = sizeof(*md);
588 
589 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
590 
591 		} else {
592 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
593 		}
594 
595 		return PACKET_RCVD;
596 	}
597 
598 	return PACKET_REJECT;
599 }
600 
601 static int gre_rcv(struct sk_buff *skb)
602 {
603 	struct tnl_ptk_info tpi;
604 	bool csum_err = false;
605 	int hdr_len;
606 
607 	hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
608 	if (hdr_len < 0)
609 		goto drop;
610 
611 	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
612 		goto drop;
613 
614 	if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
615 		     tpi.proto == htons(ETH_P_ERSPAN2))) {
616 		if (ip6erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
617 			return 0;
618 		goto out;
619 	}
620 
621 	if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
622 		return 0;
623 
624 out:
625 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
626 drop:
627 	kfree_skb(skb);
628 	return 0;
629 }
630 
631 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
632 {
633 	return iptunnel_handle_offloads(skb,
634 					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
635 }
636 
637 static void prepare_ip6gre_xmit_ipv4(struct sk_buff *skb,
638 				     struct net_device *dev,
639 				     struct flowi6 *fl6, __u8 *dsfield,
640 				     int *encap_limit)
641 {
642 	const struct iphdr *iph = ip_hdr(skb);
643 	struct ip6_tnl *t = netdev_priv(dev);
644 
645 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
646 		*encap_limit = t->parms.encap_limit;
647 
648 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
649 
650 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
651 		*dsfield = ipv4_get_dsfield(iph);
652 	else
653 		*dsfield = ip6_tclass(t->parms.flowinfo);
654 
655 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
656 		fl6->flowi6_mark = skb->mark;
657 	else
658 		fl6->flowi6_mark = t->parms.fwmark;
659 
660 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
661 }
662 
663 static int prepare_ip6gre_xmit_ipv6(struct sk_buff *skb,
664 				    struct net_device *dev,
665 				    struct flowi6 *fl6, __u8 *dsfield,
666 				    int *encap_limit)
667 {
668 	struct ipv6hdr *ipv6h;
669 	struct ip6_tnl *t = netdev_priv(dev);
670 	__u16 offset;
671 
672 	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
673 	/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
674 	ipv6h = ipv6_hdr(skb);
675 
676 	if (offset > 0) {
677 		struct ipv6_tlv_tnl_enc_lim *tel;
678 
679 		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
680 		if (tel->encap_limit == 0) {
681 			icmpv6_send(skb, ICMPV6_PARAMPROB,
682 				    ICMPV6_HDR_FIELD, offset + 2);
683 			return -1;
684 		}
685 		*encap_limit = tel->encap_limit - 1;
686 	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
687 		*encap_limit = t->parms.encap_limit;
688 	}
689 
690 	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
691 
692 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
693 		*dsfield = ipv6_get_dsfield(ipv6h);
694 	else
695 		*dsfield = ip6_tclass(t->parms.flowinfo);
696 
697 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
698 		fl6->flowlabel |= ip6_flowlabel(ipv6h);
699 
700 	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
701 		fl6->flowi6_mark = skb->mark;
702 	else
703 		fl6->flowi6_mark = t->parms.fwmark;
704 
705 	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
706 
707 	return 0;
708 }
709 
710 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
711 			       struct net_device *dev, __u8 dsfield,
712 			       struct flowi6 *fl6, int encap_limit,
713 			       __u32 *pmtu, __be16 proto)
714 {
715 	struct ip6_tnl *tunnel = netdev_priv(dev);
716 	__be16 protocol;
717 
718 	if (dev->type == ARPHRD_ETHER)
719 		IPCB(skb)->flags = 0;
720 
721 	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
722 		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
723 	else
724 		fl6->daddr = tunnel->parms.raddr;
725 
726 	if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
727 		return -ENOMEM;
728 
729 	/* Push GRE header. */
730 	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
731 
732 	if (tunnel->parms.collect_md) {
733 		struct ip_tunnel_info *tun_info;
734 		const struct ip_tunnel_key *key;
735 		__be16 flags;
736 
737 		tun_info = skb_tunnel_info(skb);
738 		if (unlikely(!tun_info ||
739 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
740 			     ip_tunnel_info_af(tun_info) != AF_INET6))
741 			return -EINVAL;
742 
743 		key = &tun_info->key;
744 		memset(fl6, 0, sizeof(*fl6));
745 		fl6->flowi6_proto = IPPROTO_GRE;
746 		fl6->daddr = key->u.ipv6.dst;
747 		fl6->flowlabel = key->label;
748 		fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
749 
750 		dsfield = key->tos;
751 		flags = key->tun_flags &
752 			(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
753 		tunnel->tun_hlen = gre_calc_hlen(flags);
754 
755 		gre_build_header(skb, tunnel->tun_hlen,
756 				 flags, protocol,
757 				 tunnel_id_to_key32(tun_info->key.tun_id),
758 				 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
759 						      : 0);
760 
761 	} else {
762 		if (tunnel->parms.o_flags & TUNNEL_SEQ)
763 			tunnel->o_seqno++;
764 
765 		gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
766 				 protocol, tunnel->parms.o_key,
767 				 htonl(tunnel->o_seqno));
768 	}
769 
770 	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
771 			    NEXTHDR_GRE);
772 }
773 
774 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
775 {
776 	struct ip6_tnl *t = netdev_priv(dev);
777 	int encap_limit = -1;
778 	struct flowi6 fl6;
779 	__u8 dsfield = 0;
780 	__u32 mtu;
781 	int err;
782 
783 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
784 
785 	if (!t->parms.collect_md)
786 		prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
787 					 &dsfield, &encap_limit);
788 
789 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
790 	if (err)
791 		return -1;
792 
793 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
794 			  skb->protocol);
795 	if (err != 0) {
796 		/* XXX: send ICMP error even if DF is not set. */
797 		if (err == -EMSGSIZE)
798 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
799 				  htonl(mtu));
800 		return -1;
801 	}
802 
803 	return 0;
804 }
805 
806 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
807 {
808 	struct ip6_tnl *t = netdev_priv(dev);
809 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
810 	int encap_limit = -1;
811 	struct flowi6 fl6;
812 	__u8 dsfield = 0;
813 	__u32 mtu;
814 	int err;
815 
816 	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
817 		return -1;
818 
819 	if (!t->parms.collect_md &&
820 	    prepare_ip6gre_xmit_ipv6(skb, dev, &fl6, &dsfield, &encap_limit))
821 		return -1;
822 
823 	if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
824 		return -1;
825 
826 	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
827 			  &mtu, skb->protocol);
828 	if (err != 0) {
829 		if (err == -EMSGSIZE)
830 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
831 		return -1;
832 	}
833 
834 	return 0;
835 }
836 
837 /**
838  * ip6gre_tnl_addr_conflict - compare packet addresses to tunnel's own
839  *   @t: the outgoing tunnel device
840  *   @hdr: IPv6 header from the incoming packet
841  *
842  * Description:
843  *   Avoid trivial tunneling loop by checking that tunnel exit-point
844  *   doesn't match source of incoming packet.
845  *
846  * Return:
847  *   1 if conflict,
848  *   0 else
849  **/
850 
851 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
852 	const struct ipv6hdr *hdr)
853 {
854 	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
855 }
856 
857 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
858 {
859 	struct ip6_tnl *t = netdev_priv(dev);
860 	int encap_limit = -1;
861 	struct flowi6 fl6;
862 	__u32 mtu;
863 	int err;
864 
865 	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
866 		encap_limit = t->parms.encap_limit;
867 
868 	if (!t->parms.collect_md)
869 		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
870 
871 	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
872 	if (err)
873 		return err;
874 
875 	err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
876 
877 	return err;
878 }
879 
880 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
881 	struct net_device *dev)
882 {
883 	struct ip6_tnl *t = netdev_priv(dev);
884 	struct net_device_stats *stats = &t->dev->stats;
885 	int ret;
886 
887 	if (!pskb_inet_may_pull(skb))
888 		goto tx_err;
889 
890 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
891 		goto tx_err;
892 
893 	switch (skb->protocol) {
894 	case htons(ETH_P_IP):
895 		ret = ip6gre_xmit_ipv4(skb, dev);
896 		break;
897 	case htons(ETH_P_IPV6):
898 		ret = ip6gre_xmit_ipv6(skb, dev);
899 		break;
900 	default:
901 		ret = ip6gre_xmit_other(skb, dev);
902 		break;
903 	}
904 
905 	if (ret < 0)
906 		goto tx_err;
907 
908 	return NETDEV_TX_OK;
909 
910 tx_err:
911 	stats->tx_errors++;
912 	stats->tx_dropped++;
913 	kfree_skb(skb);
914 	return NETDEV_TX_OK;
915 }
916 
917 static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
918 					 struct net_device *dev)
919 {
920 	struct ip6_tnl *t = netdev_priv(dev);
921 	struct dst_entry *dst = skb_dst(skb);
922 	struct net_device_stats *stats;
923 	bool truncate = false;
924 	int encap_limit = -1;
925 	__u8 dsfield = false;
926 	struct flowi6 fl6;
927 	int err = -EINVAL;
928 	__be16 proto;
929 	__u32 mtu;
930 	int nhoff;
931 	int thoff;
932 
933 	if (!pskb_inet_may_pull(skb))
934 		goto tx_err;
935 
936 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
937 		goto tx_err;
938 
939 	if (gre_handle_offloads(skb, false))
940 		goto tx_err;
941 
942 	if (skb->len > dev->mtu + dev->hard_header_len) {
943 		pskb_trim(skb, dev->mtu + dev->hard_header_len);
944 		truncate = true;
945 	}
946 
947 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
948 	if (skb->protocol == htons(ETH_P_IP) &&
949 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
950 		truncate = true;
951 
952 	thoff = skb_transport_header(skb) - skb_mac_header(skb);
953 	if (skb->protocol == htons(ETH_P_IPV6) &&
954 	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
955 		truncate = true;
956 
957 	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
958 		goto tx_err;
959 
960 	t->parms.o_flags &= ~TUNNEL_KEY;
961 	IPCB(skb)->flags = 0;
962 
963 	/* For collect_md mode, derive fl6 from the tunnel key,
964 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
965 	 */
966 	if (t->parms.collect_md) {
967 		struct ip_tunnel_info *tun_info;
968 		const struct ip_tunnel_key *key;
969 		struct erspan_metadata *md;
970 		__be32 tun_id;
971 
972 		tun_info = skb_tunnel_info(skb);
973 		if (unlikely(!tun_info ||
974 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
975 			     ip_tunnel_info_af(tun_info) != AF_INET6))
976 			goto tx_err;
977 
978 		key = &tun_info->key;
979 		memset(&fl6, 0, sizeof(fl6));
980 		fl6.flowi6_proto = IPPROTO_GRE;
981 		fl6.daddr = key->u.ipv6.dst;
982 		fl6.flowlabel = key->label;
983 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
984 
985 		dsfield = key->tos;
986 		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
987 			goto tx_err;
988 		if (tun_info->options_len < sizeof(*md))
989 			goto tx_err;
990 		md = ip_tunnel_info_opts(tun_info);
991 
992 		tun_id = tunnel_id_to_key32(key->tun_id);
993 		if (md->version == 1) {
994 			erspan_build_header(skb,
995 					    ntohl(tun_id),
996 					    ntohl(md->u.index), truncate,
997 					    false);
998 		} else if (md->version == 2) {
999 			erspan_build_header_v2(skb,
1000 					       ntohl(tun_id),
1001 					       md->u.md2.dir,
1002 					       get_hwid(&md->u.md2),
1003 					       truncate, false);
1004 		} else {
1005 			goto tx_err;
1006 		}
1007 	} else {
1008 		switch (skb->protocol) {
1009 		case htons(ETH_P_IP):
1010 			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1011 			prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
1012 						 &dsfield, &encap_limit);
1013 			break;
1014 		case htons(ETH_P_IPV6):
1015 			if (ipv6_addr_equal(&t->parms.raddr, &ipv6_hdr(skb)->saddr))
1016 				goto tx_err;
1017 			if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
1018 						     &dsfield, &encap_limit))
1019 				goto tx_err;
1020 			break;
1021 		default:
1022 			memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1023 			break;
1024 		}
1025 
1026 		if (t->parms.erspan_ver == 1)
1027 			erspan_build_header(skb, ntohl(t->parms.o_key),
1028 					    t->parms.index,
1029 					    truncate, false);
1030 		else if (t->parms.erspan_ver == 2)
1031 			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
1032 					       t->parms.dir,
1033 					       t->parms.hwid,
1034 					       truncate, false);
1035 		else
1036 			goto tx_err;
1037 
1038 		fl6.daddr = t->parms.raddr;
1039 	}
1040 
1041 	/* Push GRE header. */
1042 	proto = (t->parms.erspan_ver == 1) ? htons(ETH_P_ERSPAN)
1043 					   : htons(ETH_P_ERSPAN2);
1044 	gre_build_header(skb, 8, TUNNEL_SEQ, proto, 0, htonl(t->o_seqno++));
1045 
1046 	/* TooBig packet may have updated dst->dev's mtu */
1047 	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
1048 		dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu, false);
1049 
1050 	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1051 			   NEXTHDR_GRE);
1052 	if (err != 0) {
1053 		/* XXX: send ICMP error even if DF is not set. */
1054 		if (err == -EMSGSIZE) {
1055 			if (skb->protocol == htons(ETH_P_IP))
1056 				icmp_send(skb, ICMP_DEST_UNREACH,
1057 					  ICMP_FRAG_NEEDED, htonl(mtu));
1058 			else
1059 				icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1060 		}
1061 
1062 		goto tx_err;
1063 	}
1064 	return NETDEV_TX_OK;
1065 
1066 tx_err:
1067 	stats = &t->dev->stats;
1068 	stats->tx_errors++;
1069 	stats->tx_dropped++;
1070 	kfree_skb(skb);
1071 	return NETDEV_TX_OK;
1072 }
1073 
1074 static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
1075 {
1076 	struct net_device *dev = t->dev;
1077 	struct __ip6_tnl_parm *p = &t->parms;
1078 	struct flowi6 *fl6 = &t->fl.u.ip6;
1079 
1080 	if (dev->type != ARPHRD_ETHER) {
1081 		memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1082 		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1083 	}
1084 
1085 	/* Set up flowi template */
1086 	fl6->saddr = p->laddr;
1087 	fl6->daddr = p->raddr;
1088 	fl6->flowi6_oif = p->link;
1089 	fl6->flowlabel = 0;
1090 	fl6->flowi6_proto = IPPROTO_GRE;
1091 
1092 	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1093 		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1094 	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1095 		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1096 
1097 	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1098 	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1099 
1100 	if (p->flags&IP6_TNL_F_CAP_XMIT &&
1101 			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
1102 		dev->flags |= IFF_POINTOPOINT;
1103 	else
1104 		dev->flags &= ~IFF_POINTOPOINT;
1105 }
1106 
1107 static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
1108 					 int t_hlen)
1109 {
1110 	const struct __ip6_tnl_parm *p = &t->parms;
1111 	struct net_device *dev = t->dev;
1112 
1113 	if (p->flags & IP6_TNL_F_CAP_XMIT) {
1114 		int strict = (ipv6_addr_type(&p->raddr) &
1115 			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1116 
1117 		struct rt6_info *rt = rt6_lookup(t->net,
1118 						 &p->raddr, &p->laddr,
1119 						 p->link, NULL, strict);
1120 
1121 		if (!rt)
1122 			return;
1123 
1124 		if (rt->dst.dev) {
1125 			dev->needed_headroom = rt->dst.dev->hard_header_len +
1126 					       t_hlen;
1127 
1128 			if (set_mtu) {
1129 				dev->mtu = rt->dst.dev->mtu - t_hlen;
1130 				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1131 					dev->mtu -= 8;
1132 				if (dev->type == ARPHRD_ETHER)
1133 					dev->mtu -= ETH_HLEN;
1134 
1135 				if (dev->mtu < IPV6_MIN_MTU)
1136 					dev->mtu = IPV6_MIN_MTU;
1137 			}
1138 		}
1139 		ip6_rt_put(rt);
1140 	}
1141 }
1142 
1143 static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
1144 {
1145 	int t_hlen;
1146 
1147 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1148 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1149 
1150 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1151 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1152 	return t_hlen;
1153 }
1154 
1155 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
1156 {
1157 	ip6gre_tnl_link_config_common(t);
1158 	ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
1159 }
1160 
1161 static void ip6gre_tnl_copy_tnl_parm(struct ip6_tnl *t,
1162 				     const struct __ip6_tnl_parm *p)
1163 {
1164 	t->parms.laddr = p->laddr;
1165 	t->parms.raddr = p->raddr;
1166 	t->parms.flags = p->flags;
1167 	t->parms.hop_limit = p->hop_limit;
1168 	t->parms.encap_limit = p->encap_limit;
1169 	t->parms.flowinfo = p->flowinfo;
1170 	t->parms.link = p->link;
1171 	t->parms.proto = p->proto;
1172 	t->parms.i_key = p->i_key;
1173 	t->parms.o_key = p->o_key;
1174 	t->parms.i_flags = p->i_flags;
1175 	t->parms.o_flags = p->o_flags;
1176 	t->parms.fwmark = p->fwmark;
1177 	t->parms.erspan_ver = p->erspan_ver;
1178 	t->parms.index = p->index;
1179 	t->parms.dir = p->dir;
1180 	t->parms.hwid = p->hwid;
1181 	dst_cache_reset(&t->dst_cache);
1182 }
1183 
1184 static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
1185 			     int set_mtu)
1186 {
1187 	ip6gre_tnl_copy_tnl_parm(t, p);
1188 	ip6gre_tnl_link_config(t, set_mtu);
1189 	return 0;
1190 }
1191 
1192 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1193 	const struct ip6_tnl_parm2 *u)
1194 {
1195 	p->laddr = u->laddr;
1196 	p->raddr = u->raddr;
1197 	p->flags = u->flags;
1198 	p->hop_limit = u->hop_limit;
1199 	p->encap_limit = u->encap_limit;
1200 	p->flowinfo = u->flowinfo;
1201 	p->link = u->link;
1202 	p->i_key = u->i_key;
1203 	p->o_key = u->o_key;
1204 	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
1205 	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
1206 	memcpy(p->name, u->name, sizeof(u->name));
1207 }
1208 
1209 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1210 	const struct __ip6_tnl_parm *p)
1211 {
1212 	u->proto = IPPROTO_GRE;
1213 	u->laddr = p->laddr;
1214 	u->raddr = p->raddr;
1215 	u->flags = p->flags;
1216 	u->hop_limit = p->hop_limit;
1217 	u->encap_limit = p->encap_limit;
1218 	u->flowinfo = p->flowinfo;
1219 	u->link = p->link;
1220 	u->i_key = p->i_key;
1221 	u->o_key = p->o_key;
1222 	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
1223 	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
1224 	memcpy(u->name, p->name, sizeof(u->name));
1225 }
1226 
1227 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1228 	struct ifreq *ifr, int cmd)
1229 {
1230 	int err = 0;
1231 	struct ip6_tnl_parm2 p;
1232 	struct __ip6_tnl_parm p1;
1233 	struct ip6_tnl *t = netdev_priv(dev);
1234 	struct net *net = t->net;
1235 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1236 
1237 	memset(&p1, 0, sizeof(p1));
1238 
1239 	switch (cmd) {
1240 	case SIOCGETTUNNEL:
1241 		if (dev == ign->fb_tunnel_dev) {
1242 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1243 				err = -EFAULT;
1244 				break;
1245 			}
1246 			ip6gre_tnl_parm_from_user(&p1, &p);
1247 			t = ip6gre_tunnel_locate(net, &p1, 0);
1248 			if (!t)
1249 				t = netdev_priv(dev);
1250 		}
1251 		memset(&p, 0, sizeof(p));
1252 		ip6gre_tnl_parm_to_user(&p, &t->parms);
1253 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1254 			err = -EFAULT;
1255 		break;
1256 
1257 	case SIOCADDTUNNEL:
1258 	case SIOCCHGTUNNEL:
1259 		err = -EPERM;
1260 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1261 			goto done;
1262 
1263 		err = -EFAULT;
1264 		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1265 			goto done;
1266 
1267 		err = -EINVAL;
1268 		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1269 			goto done;
1270 
1271 		if (!(p.i_flags&GRE_KEY))
1272 			p.i_key = 0;
1273 		if (!(p.o_flags&GRE_KEY))
1274 			p.o_key = 0;
1275 
1276 		ip6gre_tnl_parm_from_user(&p1, &p);
1277 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1278 
1279 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1280 			if (t) {
1281 				if (t->dev != dev) {
1282 					err = -EEXIST;
1283 					break;
1284 				}
1285 			} else {
1286 				t = netdev_priv(dev);
1287 
1288 				ip6gre_tunnel_unlink(ign, t);
1289 				synchronize_net();
1290 				ip6gre_tnl_change(t, &p1, 1);
1291 				ip6gre_tunnel_link(ign, t);
1292 				netdev_state_change(dev);
1293 			}
1294 		}
1295 
1296 		if (t) {
1297 			err = 0;
1298 
1299 			memset(&p, 0, sizeof(p));
1300 			ip6gre_tnl_parm_to_user(&p, &t->parms);
1301 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1302 				err = -EFAULT;
1303 		} else
1304 			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1305 		break;
1306 
1307 	case SIOCDELTUNNEL:
1308 		err = -EPERM;
1309 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1310 			goto done;
1311 
1312 		if (dev == ign->fb_tunnel_dev) {
1313 			err = -EFAULT;
1314 			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1315 				goto done;
1316 			err = -ENOENT;
1317 			ip6gre_tnl_parm_from_user(&p1, &p);
1318 			t = ip6gre_tunnel_locate(net, &p1, 0);
1319 			if (!t)
1320 				goto done;
1321 			err = -EPERM;
1322 			if (t == netdev_priv(ign->fb_tunnel_dev))
1323 				goto done;
1324 			dev = t->dev;
1325 		}
1326 		unregister_netdevice(dev);
1327 		err = 0;
1328 		break;
1329 
1330 	default:
1331 		err = -EINVAL;
1332 	}
1333 
1334 done:
1335 	return err;
1336 }
1337 
1338 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1339 			 unsigned short type, const void *daddr,
1340 			 const void *saddr, unsigned int len)
1341 {
1342 	struct ip6_tnl *t = netdev_priv(dev);
1343 	struct ipv6hdr *ipv6h;
1344 	__be16 *p;
1345 
1346 	ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
1347 	ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
1348 						  t->fl.u.ip6.flowlabel,
1349 						  true, &t->fl.u.ip6));
1350 	ipv6h->hop_limit = t->parms.hop_limit;
1351 	ipv6h->nexthdr = NEXTHDR_GRE;
1352 	ipv6h->saddr = t->parms.laddr;
1353 	ipv6h->daddr = t->parms.raddr;
1354 
1355 	p = (__be16 *)(ipv6h + 1);
1356 	p[0] = t->parms.o_flags;
1357 	p[1] = htons(type);
1358 
1359 	/*
1360 	 *	Set the source hardware address.
1361 	 */
1362 
1363 	if (saddr)
1364 		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1365 	if (daddr)
1366 		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1367 	if (!ipv6_addr_any(&ipv6h->daddr))
1368 		return t->hlen;
1369 
1370 	return -t->hlen;
1371 }
1372 
1373 static const struct header_ops ip6gre_header_ops = {
1374 	.create	= ip6gre_header,
1375 };
1376 
1377 static const struct net_device_ops ip6gre_netdev_ops = {
1378 	.ndo_init		= ip6gre_tunnel_init,
1379 	.ndo_uninit		= ip6gre_tunnel_uninit,
1380 	.ndo_start_xmit		= ip6gre_tunnel_xmit,
1381 	.ndo_do_ioctl		= ip6gre_tunnel_ioctl,
1382 	.ndo_change_mtu		= ip6_tnl_change_mtu,
1383 	.ndo_get_stats64	= ip_tunnel_get_stats64,
1384 	.ndo_get_iflink		= ip6_tnl_get_iflink,
1385 };
1386 
1387 static void ip6gre_dev_free(struct net_device *dev)
1388 {
1389 	struct ip6_tnl *t = netdev_priv(dev);
1390 
1391 	gro_cells_destroy(&t->gro_cells);
1392 	dst_cache_destroy(&t->dst_cache);
1393 	free_percpu(dev->tstats);
1394 }
1395 
1396 static void ip6gre_tunnel_setup(struct net_device *dev)
1397 {
1398 	dev->netdev_ops = &ip6gre_netdev_ops;
1399 	dev->needs_free_netdev = true;
1400 	dev->priv_destructor = ip6gre_dev_free;
1401 
1402 	dev->type = ARPHRD_IP6GRE;
1403 
1404 	dev->flags |= IFF_NOARP;
1405 	dev->addr_len = sizeof(struct in6_addr);
1406 	netif_keep_dst(dev);
1407 	/* This perm addr will be used as interface identifier by IPv6 */
1408 	dev->addr_assign_type = NET_ADDR_RANDOM;
1409 	eth_random_addr(dev->perm_addr);
1410 }
1411 
1412 #define GRE6_FEATURES (NETIF_F_SG |		\
1413 		       NETIF_F_FRAGLIST |	\
1414 		       NETIF_F_HIGHDMA |	\
1415 		       NETIF_F_HW_CSUM)
1416 
1417 static void ip6gre_tnl_init_features(struct net_device *dev)
1418 {
1419 	struct ip6_tnl *nt = netdev_priv(dev);
1420 
1421 	dev->features		|= GRE6_FEATURES;
1422 	dev->hw_features	|= GRE6_FEATURES;
1423 
1424 	if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1425 		/* TCP offload with GRE SEQ is not supported, nor
1426 		 * can we support 2 levels of outer headers requiring
1427 		 * an update.
1428 		 */
1429 		if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1430 		    nt->encap.type == TUNNEL_ENCAP_NONE) {
1431 			dev->features    |= NETIF_F_GSO_SOFTWARE;
1432 			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1433 		}
1434 
1435 		/* Can use a lockless transmit, unless we generate
1436 		 * output sequences
1437 		 */
1438 		dev->features |= NETIF_F_LLTX;
1439 	}
1440 }
1441 
1442 static int ip6gre_tunnel_init_common(struct net_device *dev)
1443 {
1444 	struct ip6_tnl *tunnel;
1445 	int ret;
1446 	int t_hlen;
1447 
1448 	tunnel = netdev_priv(dev);
1449 
1450 	tunnel->dev = dev;
1451 	tunnel->net = dev_net(dev);
1452 	strcpy(tunnel->parms.name, dev->name);
1453 
1454 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1455 	if (!dev->tstats)
1456 		return -ENOMEM;
1457 
1458 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1459 	if (ret)
1460 		goto cleanup_alloc_pcpu_stats;
1461 
1462 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1463 	if (ret)
1464 		goto cleanup_dst_cache_init;
1465 
1466 	t_hlen = ip6gre_calc_hlen(tunnel);
1467 	dev->mtu = ETH_DATA_LEN - t_hlen;
1468 	if (dev->type == ARPHRD_ETHER)
1469 		dev->mtu -= ETH_HLEN;
1470 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1471 		dev->mtu -= 8;
1472 
1473 	if (tunnel->parms.collect_md) {
1474 		netif_keep_dst(dev);
1475 	}
1476 	ip6gre_tnl_init_features(dev);
1477 
1478 	return 0;
1479 
1480 cleanup_dst_cache_init:
1481 	dst_cache_destroy(&tunnel->dst_cache);
1482 cleanup_alloc_pcpu_stats:
1483 	free_percpu(dev->tstats);
1484 	dev->tstats = NULL;
1485 	return ret;
1486 }
1487 
1488 static int ip6gre_tunnel_init(struct net_device *dev)
1489 {
1490 	struct ip6_tnl *tunnel;
1491 	int ret;
1492 
1493 	ret = ip6gre_tunnel_init_common(dev);
1494 	if (ret)
1495 		return ret;
1496 
1497 	tunnel = netdev_priv(dev);
1498 
1499 	if (tunnel->parms.collect_md)
1500 		return 0;
1501 
1502 	memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1503 	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1504 
1505 	if (ipv6_addr_any(&tunnel->parms.raddr))
1506 		dev->header_ops = &ip6gre_header_ops;
1507 
1508 	return 0;
1509 }
1510 
1511 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1512 {
1513 	struct ip6_tnl *tunnel = netdev_priv(dev);
1514 
1515 	tunnel->dev = dev;
1516 	tunnel->net = dev_net(dev);
1517 	strcpy(tunnel->parms.name, dev->name);
1518 
1519 	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
1520 
1521 	dev_hold(dev);
1522 }
1523 
1524 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1525 	.handler     = gre_rcv,
1526 	.err_handler = ip6gre_err,
1527 	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1528 };
1529 
1530 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1531 {
1532 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1533 	struct net_device *dev, *aux;
1534 	int prio;
1535 
1536 	for_each_netdev_safe(net, dev, aux)
1537 		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1538 		    dev->rtnl_link_ops == &ip6gre_tap_ops ||
1539 		    dev->rtnl_link_ops == &ip6erspan_tap_ops)
1540 			unregister_netdevice_queue(dev, head);
1541 
1542 	for (prio = 0; prio < 4; prio++) {
1543 		int h;
1544 		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1545 			struct ip6_tnl *t;
1546 
1547 			t = rtnl_dereference(ign->tunnels[prio][h]);
1548 
1549 			while (t) {
1550 				/* If dev is in the same netns, it has already
1551 				 * been added to the list by the previous loop.
1552 				 */
1553 				if (!net_eq(dev_net(t->dev), net))
1554 					unregister_netdevice_queue(t->dev,
1555 								   head);
1556 				t = rtnl_dereference(t->next);
1557 			}
1558 		}
1559 	}
1560 }
1561 
1562 static int __net_init ip6gre_init_net(struct net *net)
1563 {
1564 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1565 	struct net_device *ndev;
1566 	int err;
1567 
1568 	if (!net_has_fallback_tunnels(net))
1569 		return 0;
1570 	ndev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1571 			    NET_NAME_UNKNOWN, ip6gre_tunnel_setup);
1572 	if (!ndev) {
1573 		err = -ENOMEM;
1574 		goto err_alloc_dev;
1575 	}
1576 	ign->fb_tunnel_dev = ndev;
1577 	dev_net_set(ign->fb_tunnel_dev, net);
1578 	/* FB netdevice is special: we have one, and only one per netns.
1579 	 * Allowing to move it to another netns is clearly unsafe.
1580 	 */
1581 	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1582 
1583 
1584 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1585 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1586 
1587 	err = register_netdev(ign->fb_tunnel_dev);
1588 	if (err)
1589 		goto err_reg_dev;
1590 
1591 	rcu_assign_pointer(ign->tunnels_wc[0],
1592 			   netdev_priv(ign->fb_tunnel_dev));
1593 	return 0;
1594 
1595 err_reg_dev:
1596 	free_netdev(ndev);
1597 err_alloc_dev:
1598 	return err;
1599 }
1600 
1601 static void __net_exit ip6gre_exit_batch_net(struct list_head *net_list)
1602 {
1603 	struct net *net;
1604 	LIST_HEAD(list);
1605 
1606 	rtnl_lock();
1607 	list_for_each_entry(net, net_list, exit_list)
1608 		ip6gre_destroy_tunnels(net, &list);
1609 	unregister_netdevice_many(&list);
1610 	rtnl_unlock();
1611 }
1612 
1613 static struct pernet_operations ip6gre_net_ops = {
1614 	.init = ip6gre_init_net,
1615 	.exit_batch = ip6gre_exit_batch_net,
1616 	.id   = &ip6gre_net_id,
1617 	.size = sizeof(struct ip6gre_net),
1618 };
1619 
1620 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1621 				  struct netlink_ext_ack *extack)
1622 {
1623 	__be16 flags;
1624 
1625 	if (!data)
1626 		return 0;
1627 
1628 	flags = 0;
1629 	if (data[IFLA_GRE_IFLAGS])
1630 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1631 	if (data[IFLA_GRE_OFLAGS])
1632 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1633 	if (flags & (GRE_VERSION|GRE_ROUTING))
1634 		return -EINVAL;
1635 
1636 	return 0;
1637 }
1638 
1639 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1640 			       struct netlink_ext_ack *extack)
1641 {
1642 	struct in6_addr daddr;
1643 
1644 	if (tb[IFLA_ADDRESS]) {
1645 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1646 			return -EINVAL;
1647 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1648 			return -EADDRNOTAVAIL;
1649 	}
1650 
1651 	if (!data)
1652 		goto out;
1653 
1654 	if (data[IFLA_GRE_REMOTE]) {
1655 		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1656 		if (ipv6_addr_any(&daddr))
1657 			return -EINVAL;
1658 	}
1659 
1660 out:
1661 	return ip6gre_tunnel_validate(tb, data, extack);
1662 }
1663 
1664 static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1665 				  struct netlink_ext_ack *extack)
1666 {
1667 	__be16 flags = 0;
1668 	int ret, ver = 0;
1669 
1670 	if (!data)
1671 		return 0;
1672 
1673 	ret = ip6gre_tap_validate(tb, data, extack);
1674 	if (ret)
1675 		return ret;
1676 
1677 	/* ERSPAN should only have GRE sequence and key flag */
1678 	if (data[IFLA_GRE_OFLAGS])
1679 		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1680 	if (data[IFLA_GRE_IFLAGS])
1681 		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1682 	if (!data[IFLA_GRE_COLLECT_METADATA] &&
1683 	    flags != (GRE_SEQ | GRE_KEY))
1684 		return -EINVAL;
1685 
1686 	/* ERSPAN Session ID only has 10-bit. Since we reuse
1687 	 * 32-bit key field as ID, check it's range.
1688 	 */
1689 	if (data[IFLA_GRE_IKEY] &&
1690 	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1691 		return -EINVAL;
1692 
1693 	if (data[IFLA_GRE_OKEY] &&
1694 	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1695 		return -EINVAL;
1696 
1697 	if (data[IFLA_GRE_ERSPAN_VER]) {
1698 		ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1699 		if (ver != 1 && ver != 2)
1700 			return -EINVAL;
1701 	}
1702 
1703 	if (ver == 1) {
1704 		if (data[IFLA_GRE_ERSPAN_INDEX]) {
1705 			u32 index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1706 
1707 			if (index & ~INDEX_MASK)
1708 				return -EINVAL;
1709 		}
1710 	} else if (ver == 2) {
1711 		if (data[IFLA_GRE_ERSPAN_DIR]) {
1712 			u16 dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1713 
1714 			if (dir & ~(DIR_MASK >> DIR_OFFSET))
1715 				return -EINVAL;
1716 		}
1717 
1718 		if (data[IFLA_GRE_ERSPAN_HWID]) {
1719 			u16 hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1720 
1721 			if (hwid & ~(HWID_MASK >> HWID_OFFSET))
1722 				return -EINVAL;
1723 		}
1724 	}
1725 
1726 	return 0;
1727 }
1728 
1729 static void ip6erspan_set_version(struct nlattr *data[],
1730 				  struct __ip6_tnl_parm *parms)
1731 {
1732 	if (!data)
1733 		return;
1734 
1735 	parms->erspan_ver = 1;
1736 	if (data[IFLA_GRE_ERSPAN_VER])
1737 		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1738 
1739 	if (parms->erspan_ver == 1) {
1740 		if (data[IFLA_GRE_ERSPAN_INDEX])
1741 			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1742 	} else if (parms->erspan_ver == 2) {
1743 		if (data[IFLA_GRE_ERSPAN_DIR])
1744 			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1745 		if (data[IFLA_GRE_ERSPAN_HWID])
1746 			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1747 	}
1748 }
1749 
1750 static void ip6gre_netlink_parms(struct nlattr *data[],
1751 				struct __ip6_tnl_parm *parms)
1752 {
1753 	memset(parms, 0, sizeof(*parms));
1754 
1755 	if (!data)
1756 		return;
1757 
1758 	if (data[IFLA_GRE_LINK])
1759 		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1760 
1761 	if (data[IFLA_GRE_IFLAGS])
1762 		parms->i_flags = gre_flags_to_tnl_flags(
1763 				nla_get_be16(data[IFLA_GRE_IFLAGS]));
1764 
1765 	if (data[IFLA_GRE_OFLAGS])
1766 		parms->o_flags = gre_flags_to_tnl_flags(
1767 				nla_get_be16(data[IFLA_GRE_OFLAGS]));
1768 
1769 	if (data[IFLA_GRE_IKEY])
1770 		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1771 
1772 	if (data[IFLA_GRE_OKEY])
1773 		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1774 
1775 	if (data[IFLA_GRE_LOCAL])
1776 		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1777 
1778 	if (data[IFLA_GRE_REMOTE])
1779 		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1780 
1781 	if (data[IFLA_GRE_TTL])
1782 		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1783 
1784 	if (data[IFLA_GRE_ENCAP_LIMIT])
1785 		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1786 
1787 	if (data[IFLA_GRE_FLOWINFO])
1788 		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1789 
1790 	if (data[IFLA_GRE_FLAGS])
1791 		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1792 
1793 	if (data[IFLA_GRE_FWMARK])
1794 		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1795 
1796 	if (data[IFLA_GRE_COLLECT_METADATA])
1797 		parms->collect_md = true;
1798 }
1799 
1800 static int ip6gre_tap_init(struct net_device *dev)
1801 {
1802 	int ret;
1803 
1804 	ret = ip6gre_tunnel_init_common(dev);
1805 	if (ret)
1806 		return ret;
1807 
1808 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1809 
1810 	return 0;
1811 }
1812 
1813 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1814 	.ndo_init = ip6gre_tap_init,
1815 	.ndo_uninit = ip6gre_tunnel_uninit,
1816 	.ndo_start_xmit = ip6gre_tunnel_xmit,
1817 	.ndo_set_mac_address = eth_mac_addr,
1818 	.ndo_validate_addr = eth_validate_addr,
1819 	.ndo_change_mtu = ip6_tnl_change_mtu,
1820 	.ndo_get_stats64 = ip_tunnel_get_stats64,
1821 	.ndo_get_iflink = ip6_tnl_get_iflink,
1822 };
1823 
1824 static int ip6erspan_calc_hlen(struct ip6_tnl *tunnel)
1825 {
1826 	int t_hlen;
1827 
1828 	tunnel->tun_hlen = 8;
1829 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1830 		       erspan_hdr_len(tunnel->parms.erspan_ver);
1831 
1832 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1833 	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
1834 	return t_hlen;
1835 }
1836 
1837 static int ip6erspan_tap_init(struct net_device *dev)
1838 {
1839 	struct ip6_tnl *tunnel;
1840 	int t_hlen;
1841 	int ret;
1842 
1843 	tunnel = netdev_priv(dev);
1844 
1845 	tunnel->dev = dev;
1846 	tunnel->net = dev_net(dev);
1847 	strcpy(tunnel->parms.name, dev->name);
1848 
1849 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1850 	if (!dev->tstats)
1851 		return -ENOMEM;
1852 
1853 	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1854 	if (ret)
1855 		goto cleanup_alloc_pcpu_stats;
1856 
1857 	ret = gro_cells_init(&tunnel->gro_cells, dev);
1858 	if (ret)
1859 		goto cleanup_dst_cache_init;
1860 
1861 	t_hlen = ip6erspan_calc_hlen(tunnel);
1862 	dev->mtu = ETH_DATA_LEN - t_hlen;
1863 	if (dev->type == ARPHRD_ETHER)
1864 		dev->mtu -= ETH_HLEN;
1865 	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1866 		dev->mtu -= 8;
1867 
1868 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1869 	ip6erspan_tnl_link_config(tunnel, 1);
1870 
1871 	return 0;
1872 
1873 cleanup_dst_cache_init:
1874 	dst_cache_destroy(&tunnel->dst_cache);
1875 cleanup_alloc_pcpu_stats:
1876 	free_percpu(dev->tstats);
1877 	dev->tstats = NULL;
1878 	return ret;
1879 }
1880 
1881 static const struct net_device_ops ip6erspan_netdev_ops = {
1882 	.ndo_init =		ip6erspan_tap_init,
1883 	.ndo_uninit =		ip6erspan_tunnel_uninit,
1884 	.ndo_start_xmit =	ip6erspan_tunnel_xmit,
1885 	.ndo_set_mac_address =	eth_mac_addr,
1886 	.ndo_validate_addr =	eth_validate_addr,
1887 	.ndo_change_mtu =	ip6_tnl_change_mtu,
1888 	.ndo_get_stats64 =	ip_tunnel_get_stats64,
1889 	.ndo_get_iflink =	ip6_tnl_get_iflink,
1890 };
1891 
1892 static void ip6gre_tap_setup(struct net_device *dev)
1893 {
1894 
1895 	ether_setup(dev);
1896 
1897 	dev->max_mtu = 0;
1898 	dev->netdev_ops = &ip6gre_tap_netdev_ops;
1899 	dev->needs_free_netdev = true;
1900 	dev->priv_destructor = ip6gre_dev_free;
1901 
1902 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1903 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1904 	netif_keep_dst(dev);
1905 }
1906 
1907 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1908 				       struct ip_tunnel_encap *ipencap)
1909 {
1910 	bool ret = false;
1911 
1912 	memset(ipencap, 0, sizeof(*ipencap));
1913 
1914 	if (!data)
1915 		return ret;
1916 
1917 	if (data[IFLA_GRE_ENCAP_TYPE]) {
1918 		ret = true;
1919 		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1920 	}
1921 
1922 	if (data[IFLA_GRE_ENCAP_FLAGS]) {
1923 		ret = true;
1924 		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1925 	}
1926 
1927 	if (data[IFLA_GRE_ENCAP_SPORT]) {
1928 		ret = true;
1929 		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1930 	}
1931 
1932 	if (data[IFLA_GRE_ENCAP_DPORT]) {
1933 		ret = true;
1934 		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1935 	}
1936 
1937 	return ret;
1938 }
1939 
1940 static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
1941 				 struct nlattr *tb[], struct nlattr *data[],
1942 				 struct netlink_ext_ack *extack)
1943 {
1944 	struct ip6_tnl *nt;
1945 	struct ip_tunnel_encap ipencap;
1946 	int err;
1947 
1948 	nt = netdev_priv(dev);
1949 
1950 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1951 		int err = ip6_tnl_encap_setup(nt, &ipencap);
1952 
1953 		if (err < 0)
1954 			return err;
1955 	}
1956 
1957 	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1958 		eth_hw_addr_random(dev);
1959 
1960 	nt->dev = dev;
1961 	nt->net = dev_net(dev);
1962 
1963 	err = register_netdevice(dev);
1964 	if (err)
1965 		goto out;
1966 
1967 	if (tb[IFLA_MTU])
1968 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
1969 
1970 	dev_hold(dev);
1971 
1972 out:
1973 	return err;
1974 }
1975 
1976 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1977 			  struct nlattr *tb[], struct nlattr *data[],
1978 			  struct netlink_ext_ack *extack)
1979 {
1980 	struct ip6_tnl *nt = netdev_priv(dev);
1981 	struct net *net = dev_net(dev);
1982 	struct ip6gre_net *ign;
1983 	int err;
1984 
1985 	ip6gre_netlink_parms(data, &nt->parms);
1986 	ign = net_generic(net, ip6gre_net_id);
1987 
1988 	if (nt->parms.collect_md) {
1989 		if (rtnl_dereference(ign->collect_md_tun))
1990 			return -EEXIST;
1991 	} else {
1992 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1993 			return -EEXIST;
1994 	}
1995 
1996 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
1997 	if (!err) {
1998 		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1999 		ip6gre_tunnel_link_md(ign, nt);
2000 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2001 	}
2002 	return err;
2003 }
2004 
2005 static struct ip6_tnl *
2006 ip6gre_changelink_common(struct net_device *dev, struct nlattr *tb[],
2007 			 struct nlattr *data[], struct __ip6_tnl_parm *p_p,
2008 			 struct netlink_ext_ack *extack)
2009 {
2010 	struct ip6_tnl *t, *nt = netdev_priv(dev);
2011 	struct net *net = nt->net;
2012 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2013 	struct ip_tunnel_encap ipencap;
2014 
2015 	if (dev == ign->fb_tunnel_dev)
2016 		return ERR_PTR(-EINVAL);
2017 
2018 	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
2019 		int err = ip6_tnl_encap_setup(nt, &ipencap);
2020 
2021 		if (err < 0)
2022 			return ERR_PTR(err);
2023 	}
2024 
2025 	ip6gre_netlink_parms(data, p_p);
2026 
2027 	t = ip6gre_tunnel_locate(net, p_p, 0);
2028 
2029 	if (t) {
2030 		if (t->dev != dev)
2031 			return ERR_PTR(-EEXIST);
2032 	} else {
2033 		t = nt;
2034 	}
2035 
2036 	return t;
2037 }
2038 
2039 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
2040 			     struct nlattr *data[],
2041 			     struct netlink_ext_ack *extack)
2042 {
2043 	struct ip6_tnl *t = netdev_priv(dev);
2044 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
2045 	struct __ip6_tnl_parm p;
2046 
2047 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2048 	if (IS_ERR(t))
2049 		return PTR_ERR(t);
2050 
2051 	ip6gre_tunnel_unlink_md(ign, t);
2052 	ip6gre_tunnel_unlink(ign, t);
2053 	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
2054 	ip6gre_tunnel_link_md(ign, t);
2055 	ip6gre_tunnel_link(ign, t);
2056 	return 0;
2057 }
2058 
2059 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
2060 {
2061 	struct net *net = dev_net(dev);
2062 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
2063 
2064 	if (dev != ign->fb_tunnel_dev)
2065 		unregister_netdevice_queue(dev, head);
2066 }
2067 
2068 static size_t ip6gre_get_size(const struct net_device *dev)
2069 {
2070 	return
2071 		/* IFLA_GRE_LINK */
2072 		nla_total_size(4) +
2073 		/* IFLA_GRE_IFLAGS */
2074 		nla_total_size(2) +
2075 		/* IFLA_GRE_OFLAGS */
2076 		nla_total_size(2) +
2077 		/* IFLA_GRE_IKEY */
2078 		nla_total_size(4) +
2079 		/* IFLA_GRE_OKEY */
2080 		nla_total_size(4) +
2081 		/* IFLA_GRE_LOCAL */
2082 		nla_total_size(sizeof(struct in6_addr)) +
2083 		/* IFLA_GRE_REMOTE */
2084 		nla_total_size(sizeof(struct in6_addr)) +
2085 		/* IFLA_GRE_TTL */
2086 		nla_total_size(1) +
2087 		/* IFLA_GRE_ENCAP_LIMIT */
2088 		nla_total_size(1) +
2089 		/* IFLA_GRE_FLOWINFO */
2090 		nla_total_size(4) +
2091 		/* IFLA_GRE_FLAGS */
2092 		nla_total_size(4) +
2093 		/* IFLA_GRE_ENCAP_TYPE */
2094 		nla_total_size(2) +
2095 		/* IFLA_GRE_ENCAP_FLAGS */
2096 		nla_total_size(2) +
2097 		/* IFLA_GRE_ENCAP_SPORT */
2098 		nla_total_size(2) +
2099 		/* IFLA_GRE_ENCAP_DPORT */
2100 		nla_total_size(2) +
2101 		/* IFLA_GRE_COLLECT_METADATA */
2102 		nla_total_size(0) +
2103 		/* IFLA_GRE_FWMARK */
2104 		nla_total_size(4) +
2105 		/* IFLA_GRE_ERSPAN_INDEX */
2106 		nla_total_size(4) +
2107 		0;
2108 }
2109 
2110 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
2111 {
2112 	struct ip6_tnl *t = netdev_priv(dev);
2113 	struct __ip6_tnl_parm *p = &t->parms;
2114 	__be16 o_flags = p->o_flags;
2115 
2116 	if (p->erspan_ver == 1 || p->erspan_ver == 2) {
2117 		if (!p->collect_md)
2118 			o_flags |= TUNNEL_KEY;
2119 
2120 		if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, p->erspan_ver))
2121 			goto nla_put_failure;
2122 
2123 		if (p->erspan_ver == 1) {
2124 			if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
2125 				goto nla_put_failure;
2126 		} else {
2127 			if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, p->dir))
2128 				goto nla_put_failure;
2129 			if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, p->hwid))
2130 				goto nla_put_failure;
2131 		}
2132 	}
2133 
2134 	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
2135 	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
2136 			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
2137 	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
2138 			 gre_tnl_flags_to_gre_flags(o_flags)) ||
2139 	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
2140 	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
2141 	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
2142 	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
2143 	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
2144 	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
2145 	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
2146 	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
2147 	    nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
2148 		goto nla_put_failure;
2149 
2150 	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
2151 			t->encap.type) ||
2152 	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
2153 			 t->encap.sport) ||
2154 	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
2155 			 t->encap.dport) ||
2156 	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
2157 			t->encap.flags))
2158 		goto nla_put_failure;
2159 
2160 	if (p->collect_md) {
2161 		if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
2162 			goto nla_put_failure;
2163 	}
2164 
2165 	return 0;
2166 
2167 nla_put_failure:
2168 	return -EMSGSIZE;
2169 }
2170 
2171 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
2172 	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
2173 	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
2174 	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
2175 	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
2176 	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
2177 	[IFLA_GRE_LOCAL]       = { .len = sizeof_field(struct ipv6hdr, saddr) },
2178 	[IFLA_GRE_REMOTE]      = { .len = sizeof_field(struct ipv6hdr, daddr) },
2179 	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
2180 	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
2181 	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
2182 	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
2183 	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
2184 	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
2185 	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
2186 	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
2187 	[IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
2188 	[IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
2189 	[IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
2190 	[IFLA_GRE_ERSPAN_VER]	= { .type = NLA_U8 },
2191 	[IFLA_GRE_ERSPAN_DIR]	= { .type = NLA_U8 },
2192 	[IFLA_GRE_ERSPAN_HWID]	= { .type = NLA_U16 },
2193 };
2194 
2195 static void ip6erspan_tap_setup(struct net_device *dev)
2196 {
2197 	ether_setup(dev);
2198 
2199 	dev->max_mtu = 0;
2200 	dev->netdev_ops = &ip6erspan_netdev_ops;
2201 	dev->needs_free_netdev = true;
2202 	dev->priv_destructor = ip6gre_dev_free;
2203 
2204 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
2205 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
2206 	netif_keep_dst(dev);
2207 }
2208 
2209 static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
2210 			     struct nlattr *tb[], struct nlattr *data[],
2211 			     struct netlink_ext_ack *extack)
2212 {
2213 	struct ip6_tnl *nt = netdev_priv(dev);
2214 	struct net *net = dev_net(dev);
2215 	struct ip6gre_net *ign;
2216 	int err;
2217 
2218 	ip6gre_netlink_parms(data, &nt->parms);
2219 	ip6erspan_set_version(data, &nt->parms);
2220 	ign = net_generic(net, ip6gre_net_id);
2221 
2222 	if (nt->parms.collect_md) {
2223 		if (rtnl_dereference(ign->collect_md_tun_erspan))
2224 			return -EEXIST;
2225 	} else {
2226 		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
2227 			return -EEXIST;
2228 	}
2229 
2230 	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
2231 	if (!err) {
2232 		ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
2233 		ip6erspan_tunnel_link_md(ign, nt);
2234 		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
2235 	}
2236 	return err;
2237 }
2238 
2239 static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu)
2240 {
2241 	ip6gre_tnl_link_config_common(t);
2242 	ip6gre_tnl_link_config_route(t, set_mtu, ip6erspan_calc_hlen(t));
2243 }
2244 
2245 static int ip6erspan_tnl_change(struct ip6_tnl *t,
2246 				const struct __ip6_tnl_parm *p, int set_mtu)
2247 {
2248 	ip6gre_tnl_copy_tnl_parm(t, p);
2249 	ip6erspan_tnl_link_config(t, set_mtu);
2250 	return 0;
2251 }
2252 
2253 static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
2254 				struct nlattr *data[],
2255 				struct netlink_ext_ack *extack)
2256 {
2257 	struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
2258 	struct __ip6_tnl_parm p;
2259 	struct ip6_tnl *t;
2260 
2261 	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
2262 	if (IS_ERR(t))
2263 		return PTR_ERR(t);
2264 
2265 	ip6erspan_set_version(data, &p);
2266 	ip6gre_tunnel_unlink_md(ign, t);
2267 	ip6gre_tunnel_unlink(ign, t);
2268 	ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
2269 	ip6erspan_tunnel_link_md(ign, t);
2270 	ip6gre_tunnel_link(ign, t);
2271 	return 0;
2272 }
2273 
2274 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
2275 	.kind		= "ip6gre",
2276 	.maxtype	= IFLA_GRE_MAX,
2277 	.policy		= ip6gre_policy,
2278 	.priv_size	= sizeof(struct ip6_tnl),
2279 	.setup		= ip6gre_tunnel_setup,
2280 	.validate	= ip6gre_tunnel_validate,
2281 	.newlink	= ip6gre_newlink,
2282 	.changelink	= ip6gre_changelink,
2283 	.dellink	= ip6gre_dellink,
2284 	.get_size	= ip6gre_get_size,
2285 	.fill_info	= ip6gre_fill_info,
2286 	.get_link_net	= ip6_tnl_get_link_net,
2287 };
2288 
2289 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
2290 	.kind		= "ip6gretap",
2291 	.maxtype	= IFLA_GRE_MAX,
2292 	.policy		= ip6gre_policy,
2293 	.priv_size	= sizeof(struct ip6_tnl),
2294 	.setup		= ip6gre_tap_setup,
2295 	.validate	= ip6gre_tap_validate,
2296 	.newlink	= ip6gre_newlink,
2297 	.changelink	= ip6gre_changelink,
2298 	.get_size	= ip6gre_get_size,
2299 	.fill_info	= ip6gre_fill_info,
2300 	.get_link_net	= ip6_tnl_get_link_net,
2301 };
2302 
2303 static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly = {
2304 	.kind		= "ip6erspan",
2305 	.maxtype	= IFLA_GRE_MAX,
2306 	.policy		= ip6gre_policy,
2307 	.priv_size	= sizeof(struct ip6_tnl),
2308 	.setup		= ip6erspan_tap_setup,
2309 	.validate	= ip6erspan_tap_validate,
2310 	.newlink	= ip6erspan_newlink,
2311 	.changelink	= ip6erspan_changelink,
2312 	.get_size	= ip6gre_get_size,
2313 	.fill_info	= ip6gre_fill_info,
2314 	.get_link_net	= ip6_tnl_get_link_net,
2315 };
2316 
2317 /*
2318  *	And now the modules code and kernel interface.
2319  */
2320 
2321 static int __init ip6gre_init(void)
2322 {
2323 	int err;
2324 
2325 	pr_info("GRE over IPv6 tunneling driver\n");
2326 
2327 	err = register_pernet_device(&ip6gre_net_ops);
2328 	if (err < 0)
2329 		return err;
2330 
2331 	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
2332 	if (err < 0) {
2333 		pr_info("%s: can't add protocol\n", __func__);
2334 		goto add_proto_failed;
2335 	}
2336 
2337 	err = rtnl_link_register(&ip6gre_link_ops);
2338 	if (err < 0)
2339 		goto rtnl_link_failed;
2340 
2341 	err = rtnl_link_register(&ip6gre_tap_ops);
2342 	if (err < 0)
2343 		goto tap_ops_failed;
2344 
2345 	err = rtnl_link_register(&ip6erspan_tap_ops);
2346 	if (err < 0)
2347 		goto erspan_link_failed;
2348 
2349 out:
2350 	return err;
2351 
2352 erspan_link_failed:
2353 	rtnl_link_unregister(&ip6gre_tap_ops);
2354 tap_ops_failed:
2355 	rtnl_link_unregister(&ip6gre_link_ops);
2356 rtnl_link_failed:
2357 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2358 add_proto_failed:
2359 	unregister_pernet_device(&ip6gre_net_ops);
2360 	goto out;
2361 }
2362 
2363 static void __exit ip6gre_fini(void)
2364 {
2365 	rtnl_link_unregister(&ip6gre_tap_ops);
2366 	rtnl_link_unregister(&ip6gre_link_ops);
2367 	rtnl_link_unregister(&ip6erspan_tap_ops);
2368 	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
2369 	unregister_pernet_device(&ip6gre_net_ops);
2370 }
2371 
2372 module_init(ip6gre_init);
2373 module_exit(ip6gre_fini);
2374 MODULE_LICENSE("GPL");
2375 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
2376 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
2377 MODULE_ALIAS_RTNL_LINK("ip6gre");
2378 MODULE_ALIAS_RTNL_LINK("ip6gretap");
2379 MODULE_ALIAS_RTNL_LINK("ip6erspan");
2380 MODULE_ALIAS_NETDEV("ip6gre0");
2381